Pericyte sGC signaling dictates tumor vessel formation and tumor microenvironment

Pericytes and endothelial cells (ECs) are building blocks of blood vessels. While the contributions of ECs to tumor angiogenesis and the tumor microenvironment are well established and multiple drugs that targeting ECs have been developed for clinic use to treat cancers, the underlying mechanisms of pericyte in supporting tumor vessel and in shaping tumor microenvironment remains largely unexplored and no pericyte targeting strategies have been approved yet. This study employs targeted deletion of the NO receptor sGC in pericytes and utilizes single-cell RNA sequencing to elucidate its impact on the tumor microenvironment. The results unveil a disruptive effect on EC-pericyte interactions, subsequently impeding Notch-mediated intercellular crosstalk and prompting extensive transcriptomic reprogramming in both cell types. This vascular alteration further relays to neighboring cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) through paracrine signaling, collectively suppressing tumor growth. Importantly, the inhibition of pericyte sGC has limited influence on quiescent vessels but significantly sensitizes angiogenic vessels to anti-angiogenic treatment. In conclusion, this study underscores the vital role of pericytes in governing tumor vessels and the tumor microenvironment, suggesting that targeting pericyte sGC holds promise for enhancing anti-angiogenic therapy. Overall design: LLC tumor of both three Gucy1b1 flox/flox (CT/Ctr) and Cspg4-CreER^T2::Gucyc1b1 flox/flox (KO/?pc) C57BL/6 mice were both sequenced using 10X chromium 3' scRNA-seq protocol separately to produce two libraries followed by further analysis.

周细胞（pericytes）与内皮细胞（endothelial cells, ECs）是血管的核心构成单元。尽管内皮细胞在肿瘤血管生成及肿瘤微环境中的作用已被广泛证实，多款靶向内皮细胞的抗癌药物也已获批进入临床，但周细胞在维持肿瘤血管、塑造肿瘤微环境过程中的潜在机制仍未得到充分探索，目前尚无获批的周细胞靶向治疗策略。本研究通过靶向敲除周细胞内的一氧化氮受体可溶性鸟苷酸环化酶（soluble guanylyl cyclase, sGC），并借助单细胞RNA测序（single-cell RNA sequencing）阐明其对肿瘤微环境的调控作用。研究结果揭示了该操作对内皮细胞-周细胞互作的破坏效应，进而阻断Notch介导的细胞间通讯，并促使两种细胞发生广泛的转录组重编程。这种血管重塑进一步通过旁分泌信号传导影响邻近的癌症相关成纤维细胞（cancer-associated fibroblasts, CAFs）与肿瘤相关巨噬细胞（tumor-associated macrophages, TAMs），最终协同抑制肿瘤生长。值得关注的是，抑制周细胞sGC对静息血管的影响较为有限，却可显著增强血管生成血管对抗血管生成治疗的敏感性。综上，本研究证实了周细胞在调控肿瘤血管与肿瘤微环境中的关键作用，提示靶向周细胞sGC有望增强抗血管生成治疗的疗效。实验整体设计：分别对Gucy1b1 flox/flox（对照组，CT/Ctr）与Cspg4-CreER^T2::Gucyc1b1 flox/flox（敲除组，KO/?pc）C57BL/6小鼠的3个路易斯肺癌（Lewis lung carcinoma, LLC）肿瘤组织进行测序，采用10X Chromium 3' 单细胞RNA测序（scRNA-seq）方案构建两个文库，随后开展后续分析。